Automatic pawl-operating mechanism.



No. 876,752. PATENTED JAN. 14, 1908. w. E. WALDRON.

AUTOMATIC PAWL OPERATING MECHANISM APPLICATION FILED MAY 18, 1907.

I W/TNESSES I E I Nl ENTOI? 7727Zz'am E/hQZrZz'an/ ATTOFNEYS r m TE sTA ns' PATENT OFFICE.

' WILLIAM EDWARD WALDRON', OF NEW CASTLE, PENNSYLVANIA.

AUTOMATIC PAWL-OPERATING MECHANISM.

.Specificationof Letters Patent. Application filed May 18.15907. Serial Ni). 374.413.

Patented 14, 190 8.

To all whom it may concern: Be it known that I, WILLIAM EDWARD WALDRON, a citizen of the United States, and

a resident of New. Castle, in the'county of Lawrence'and State of Pennsylvania, have invented a new and Improved Automatic Pawl-Operating Mechanism, of which the following is a full,- clear, and eXact desc'ription.

. The object of the invention is to provide a new and improved pawl operating mechan ism, designed for use on pawl and ratchet devices employed for traveling cranes and other machinery and devices, and arranged to hold the pawl out of engagement with the ratchet wheel when the latter turns forward, and to immediatelyswing the pawl into looking engagement with the ratchet wheel whenever the latter tends to turn in the reverse direction, thus holding the ratchet wheel against return movement.

The inventionconsists of novel features and parts and combinationsof the same, which will be more fully described hereinafter and then pointed out in the claims.

A practical embodiment ofthe invention is representedin the accompanying drawings forming a part ofthis specification, in which similar characters of reference indicate corresponding parts in both views.

Figure 1 is a face view of the improvement', parts being in section, and Fig.2 is' a transverse section of the same on the line 2-2 of Fig. 1.

The ratchet wheel Ais secured to the shaft B rotating forwardly in the direction of the arrow at, and the said shaft B is j ournaled in suitable bearings C on which are fulcrumed the pawls Dand D adapted to engage the teeth of the ratchet wheel A. The pawls D and D are pivotally connected by links E' and E with an equalizing lever F mounted to turn on a pivot G held on a friction device H engaging the hub A of the ratchet wheel A.

The frictiondevice H consists preferabl of the friction bands H", H connected wit each other at one end by a link I and at the other end by a pin J and spring K, to hold the friction bands in contact with the The friction band H is extended beyond'the link I as at H andthis extension carries the pivot G previously referred to. Now when the ratchet wheel'A turns in the direction of the arrow (1 then the friction device H tends to turn with. it, and in doing so the, pivot pin G is carried forwardly so that the equalizing lever F and the links E, E swing the pawlsD, D outward out of engagementwith the ratchet wheel M The outward swinging movement of the pawl D is limited by a suitable sto L held on the bearing C, and the outwar swinging movement of .the pawl D is limited by the other pawl D. Now when the rotary motion of the ratchet wheel A in the direction of the arrow a ceases, and the wheel A tends to turn in the opposite direction, then the friction device H in turning with the ratchet wheel A causes the pivot G to travel rearwardly, whereby the equalizing lever F and the links E, E pull on the pawls D, D, thusmoving the same into engagement with the ratchet wheel .A, to hold the latter against return movement.

Although I have shown and described the improvement in connection with two pawls D, D, it is evident that the said device may be used for operating'a single pawl by makof a friction device in connection therewith,

said device comprising friction-bands having a yielding connection at one end and a link connection at the other end, one of said ba'ndsbeing extended at the link connection, an equalizing. lever pivoted by its center to the extended portion, pawls normally engaging the ratchet wheel, and links connecting the ends of the equalizing lever with the respective pawls, whereby when the ratchet wheel is rotated in a reverse direction, the pawls will be moved out of contact with the wheel.

2. The combination with a ratchet wheel, of pawls normally engaging the wheel, a fric- 2 emcee tion device in connection with the hub of the In testimony whereof I have signed my ratchet wheel, an equalizing lever pivoted by name to this specification in the presence of its center to the friction device, links 0011- two subscribing Witnesses. neetin the ends of the lever with the respeo- WILLIAM EDWARD WALDRON.

5 tive pawls whereby when the ratchet Wheel i/Vitnesses:

is rotated in areverse directien, the pewls will W. L. WIER, be moved out of Contact therewith. H. A. WILKINsON. 

